carbon tetrabromide; triphenylphosphine in dichloromethane

triphenylphosphine in dichloromethane; ethyl acetate

1: sodium hydrogencarbonate 2: triphenylphosphine; bromine / dichloromethane View Scheme

1: sodium hydrogencarbonate 2: triphenylphosphine; bromine / dichloromethane View Scheme

potassium tert-butylate in tetrahydrofuran; diethyl ether

1.1: caesium carbonate / N,N-dimethyl-formamide / 12 h / 20 °C 2.1: tetrahydrofuran; methanol / 20 °C / NaOAc-AcOH buffer 2.2: 2 h / 20 °C 3.1: silver carbonate / N,N-dimethyl-formamide / 100 °C 4.1: bromine / acetic acid / 1 h / 20 °C 4.2: 1 h 5.1: triethylamine / dichloromethane; tetrahydrofuran / 20 °C 5.2: 6 h View Scheme